From owner-freebsd-current Thu Mar 14 2: 3: 6 2002 Delivered-To: freebsd-current@freebsd.org Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by hub.freebsd.org (Postfix) with ESMTP id C467437B405 for ; Thu, 14 Mar 2002 02:03:03 -0800 (PST) Received: by elvis.mu.org (Postfix, from userid 1192) id A0CB0AE24A; Thu, 14 Mar 2002 02:03:03 -0800 (PST) Date: Thu, 14 Mar 2002 02:03:03 -0800 From: Alfred Perlstein To: Poul-Henning Kamp Cc: David Greenman , John Indra , freebsd-current@FreeBSD.ORG Subject: Re: malloc() and the stock Perl in -CURRENT (and -STABLE) Message-ID: <20020314100303.GM74829@elvis.mu.org> References: <20020314092847.GL74829@elvis.mu.org> <841.1016099616@critter.freebsd.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <841.1016099616@critter.freebsd.dk> User-Agent: Mutt/1.3.27i Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG * Poul-Henning Kamp [020314 01:53] wrote: > In message <20020314092847.GL74829@elvis.mu.org>, Alfred Perlstein writes: > > > >Have you thought about issuing a madvise(MADV_WILLNEED) after the > >brk/mmap call in malloc, at least doing it when it's called via > >realloc, this might get rid of the superfolous (sp?) page faults > >that David Greenman reported. > > It would be much more valuable to add a > mremap(void *from, void *to, size_t length); > > since that can _solve_ the problem in _all_ cases, rather than > add more or less byzantine workarounds for silly benchmarks. You're right that it would be a better optimization, however it's much more code to write than simply passing a flag down to the code responsible for the allocation especially when you _know_ you'll need it. I may be wrong about MADV_WILLNEED making any difference anyhow. :) -- -Alfred Perlstein [alfred@freebsd.org] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message